Health commodities inventory management performance and associated challenges in selected public health facilities of South Gondar Zone, Amhara Region, North Central Ethiopia: A mixed-methods cross-sectional study - Zewdu Tessema; Tesfaye Tsigu; Zelalem Tilahun; Gashew Tessema; Ayenew Berhan; Eskinder Eshetu Ali (PLoS ONE, 2026)